Comparison of Precipitating Cumulus Cells:Model-Generated Versus Radar-Observed.

摘要

The purpose of this study was twofold: to evaluate the ability of a circularly symmetric two-cylinder model of a precipitating cumulus cell to simulate radar-observed cells, and to ascertain to what accuracy the model input variables need to be known to obtain realistic results. Data from GATE were used, in part because the tropical atmosphere during the experiment contained relatively little vertical wind shear. Cells organized into two types of mesoscale features, a line and a cluster, were simulated. Because of the variability observed in the cell characteristics, the mesoscale features were idealized into geometrically simple configurations of 'representative' cells. The representative cells were geometrically compatible with the model and had dimensions based on the average sizes of observed cells. The size of the model inner cylinder, assumed to be the region of active convection, was estimated from the areas of observed reflectivity cores. The size of the outer cylinder, analogous to the environment of the cells, was estimated from distances between cells in the mesoscale features. This idealization process produced what appeared to be realistic dimensions.